Study of Lengths from the Upper Incisor to Left and Right Mainstem Bronchial Carina in Korean Adults Using a Fibroptic Bronchoscope / 대한마취과학회지

BACKGROUND: Accurate knowledge of mainstem bronchial lengths are required to prevent malpositioning of double lumen endobronchial tubes (DLT). Therefore we evaluated the length of the mainstem bronchus in Korean adults who had no abnormalities in both mainstem bronchus. METHODS: Two-hundred Thirty-seven patients were composed of One-hundred one males and One- hundred Thirty-six females who underwent elective surgery. After an endotracheal tube was placed, we measured the length from the upper incisor to the tracheal carina, the right mainstem bronchial carina, and the left mainstem bronchial carina using a fiberoptic bronchoscope. RESULTS: The lengths from the upper incisor to the carina of a male and female were 26.8 +/- 1.8 cm and 23.6 +/- 1.9 cm respectively, and the correlations between their length and height are significant for male and female (r = 0.32, P < 0.01 and r = 0.56, p < 0.0001). The lengths from the upper incisor to the right mainstem bronchial carina of male and female were 29.0 2.0 cm and 25.3 2.2 cm respectively, and the correlations between their length and height are significant for male and female (r = 0.39, P < 0.0001 and r = 0.59, P < 0.0001). The lengths from the upper incisor to the left mainstem bronchial carina of male and female were 32.0 2.1 cm and 28.5 2.1 cm respectively, and the correlations between their length and height are significant for male and female (r = 0.45, P < 0.0001 and r = 0.60, P < 0.0001). CONCLUSIONS: We found that as the height of patients increased, the length from the upper incisor to the carina, the right mainstem bronchial carina, and the left mainstem bronchial carina increased. Nevertheless,it should be understood that the length of DLT insertion at any given height is still normally distributed, and correct DLT positioning should always be confirmed fiberoptically after the initial placement.

A Comparison of the Effects of Different Types of Laryngoscope on Hemodynamics: McCoy Versus the Macintosh Blade / 대한마취과학회지

BACKGROUND: This study was designed to compare the hemodynamic changes in response to direct laryngoscopy of the McCoy blade and the Macintosh blade. METHODS: Sixty patients scheduled for elective gynecologic surgery were randomly allocated into two groups. The induction of anesthesia was done with thiopental sodium 5 mg/kg, fentanyl 2 mcg/kg, vecuronium 0.1 mg/kg. When the train of four arrived came at 0/4, the vocal cords were visualized with either the McCoy or the Macintosh laryngoscope blade for 10 seconds. Heart rate and blood pressure were recorded at 1 minute intervals for 5 minutes. RESULTS: Laryngoscopy caused significant increases in arterial blood pressure in both groups, while it had no effect on heart rate in either group. There were no significant differences in blood pressure and heart rate responses to laryngoscopy in the blades. CONCLUSIONS: The McCoy and the Macintosh blade show similar changes in heart rate and blood pressure after laryngoscopy.

The Depth of Insertion for Left-Sided Double-Lumen Endotracheal Tube is Correlated with the Height and the Length of Sternocleidomastoid Muscle / 대한마취과학회지

BACKGREOUND: When a double-lumen endotracheal tube (DLT) is used for one-lung ventilation, its position should be accurate. But only a few studies has been performed about how to predict the depth of insertion for DLT preoperatively. The purpose of this study is to investigate which physical measurements are correlated with the depth of insertion for left-sided DLT and how the depth of insertion for DLT can be explained with these physical measurements. METHODS: After placing a 5 cm-high pillow under the patient's head, we intubated left-sided disposable DLT (BronchocathTM, Mallinckrodt medical Ltd, USA) in 65 adults. We tape-measured sternocleidomastoid muscle (SCM) length and sternal length. We positioned the proximal margin of the bronchial cuff of DLT just below carinal bifurcation through fiberoptic bronchoscope, and recorded the depth of insertion for DLT at the upper incisor level. RESULTS: The depth of insertion for DLT was correlated with both height (y=3.96+0.15x, r2=0.51, p=0.0001) and SCM length (y=16.73+0.82x, r2=0.49, p=0.0001). Sternal length (r2=0.11, p=0.0081) was weakly correlated with the depth of insertion for DLT. The best regression model was depth of insertion for DLT (cm)=6.88+0.09 height (cm)x0.46 SCM length (cm). CONCLUSIONS: The depth of insertion for DLT is correlated with SCM length as well as height. So we may use them in predicting the depth of insertion for DLT.

Endotracheal Intubation Using Laryngeal Mask Airway in a Patient with a Difficult Airway: A case report / 대한마취과학회지

Laryngeal mask airway (LMA) was designed as a new concept of airway management in anesthetic practice and has been successfully used in patients with difficult endotracheal intubation due to an abnormal upper airways. When It is in good position, one can cannulate the trachea either blindly or fiberoptic brochoscopically. In a patient with short neck and large breast, we were forced to use an emergency LMA because couldn't insert the laryngoscope. We decided to replace the LMA with an endotracheal tube to secure a definite airway. A fiberoptic bronchoscope was passed through both the endotracheal tube and the LMA to achieve endotracheal intubation. Then we attempted to remove the LMA for safe and smooth awakening. But the LMA coudln't be removed while keeping the LMA and the endotracheal tube in position. Therefore, surgery had to be proceeded with both the LMA and the endotracheal tube in place and all of which were removed after the surgical procedure. We conclude that the LMA is very useful as an aid of endotracheal intubation in patients with difficult airway.

Arterial Blood Pressure and Heart Rate Response to Lightwand or Direct Laryngoscopy for Endotracheal Intubation / 대한마취과학회지

BACKGROUND: Tracheal intubation commonly results in sympathetic stimulation manifested by increased heart rate and arterial blood pressure. This study was carried out to determine whether lightwand would result in less hemodynamic changes than direct laryngoscopy. METHODS: With informed consent, fourty healthy female patients scheduled of elective surgical procedures were randomly allocated into two groups; lightwand (LW) or direct laryngoscopy (DL) group. Mean arterial pressure (MAP) and heart rate (HR) were recorded upon arrival. Under a standardized anesthetic technique, the patients were intubated either with no. 3 curved blade direct laryngoscopy (DL group) or with lightwand (LW group). The MAP and HR were recorded before intubation and every 1 minutes following intubaion. Time to intubation (TTI) was also recorded. All patients were intubated by a same fourth grade resident. RESULTS: Fourty patients were studied. Every intubation was successed in first attempt. The TTI was significantly shorter in LW group. Even while there was no significant difference in HR changes, there was significant difference in the increase of MAP following intubation. The increase of MAP was significantly greater with DL than with LW. CONCLUSIONS: This study suggests that lightwand intubation requires shorter TTI and may give rise to less blood pressure change than direct laryngoscopy. So we found no difference in disadvantage and may offers advantage in terms of hemodynamic stability.

Metric Study of Upper Airway and Trachea in Nomal Korean Adults uing Fiberoptic Bronchoscopy: Study of endotracheal tube fixation positioning in adults / 대한마취과학회지

BACKGROUND: Neck flexion risks endobroncheal intubation when the tracheal tube is not in the proper position. So accurate knowledge of upper airway length is required to prevent malpositioning of endotracheal tubes. Therefore we evaluated the length of various portions of upper airway in Korean adults (n=500) who had no abnormality of upper airway. METHODS: Five hundred patients, composed of 198 males and 302 females who underwent elective surgery, were included in this study. After endotracheal tube was placed under general anesthesia, we measured the distance from tube machine-end to upper incisor (value 1), from tube machine-end to inferior margin of cricothyroid membrane (value 2), and from tube machine-end to carina (value 3) by means of fiberoptic bronchoscopy. RESULTS: The mean length between upper incisor and inferior margin of cricothyroid membrane (value 2 - value 1) was 12.7 cm in males and 11.6 cm in females, while the mean length between superior margin of cricoid cartilage and carina (value 3 - value 2) was 12.9 cm in males and 11.3 cm in females. So the mean length between upper incisor and the mid portion of trachea was nearly 19.6 cm in males and 17.7 cm in females. CONCLUSIONS: We believe that, based on the findings in this study, the safety length for endotracheal tube fixation is 20 cm in Korean adult males and 18 cm in Korean adult females.